1.7.7 Predefined Macros
The following macros are already defined by the compiler and cannot be changed.
| __LINE__ | A decimal constant representing the current line number. |
| __FILE__ | A string representing the current name of the source code file. |
| __DATE__ | A string representing the current date when compiling began for the current source file. It is in the format “mmm dd yyyy”, the same as what is generated by the asctime function. |
| __TIME__ | A string literal representing the current time when cimpiling began for the current source file. It is in the format “hh:mm:ss”, the same as what is generated by the asctime function. |
| __STDC__ | The decimal constant 1. Used to indicate if this is a standard C compiler. |